Printing press



E. D. NASH PRINTING PRESS April 26, 1966 2 Sheets-Sheet 1 Filed Sept. 50, 1965 HIM.

wwmmmmmkkm HOMEE T DE April 26, 1966 E. D, NASH 3,247,790

PRINTING PRESS Filed Sept. 30, 1963 2 Sheets-Sheet a FIG. 2

LITHOGRAPHIC OFFSET FIG. 3

INVENTOR. E. DALE NASH ATTORNEY United States Patento 3,247,790 PRINTING PRESS Elmer D. Nash, Dayton, hio, assignor to Harris-Intertype Corporation, Cleveland, Ohio, a corporation of Delaware Filed Sept. 30, 1963, Ser. No. 314,577 2 Claims. (Cl. 101-437) This invention relates to a two-color rotary printing press adapted primarily to print by the direct letterpress process, and in the preferred form of the invention, to alternatively print by the offset process also. The present application is a continuation-impart of my earlier application Ser. No. 138,311, filed September 15, 1961, now abandoned.

The primary object of the invention is to provide such a letterpress with the cylinders so constructed and arranged as to permit easy access to all of the cylinders of the two units by an operator standing in one position, whereby all necessary work in installing, removing, or adjusting flexible members on the cylinders, or in cleaning the cylinders is greatly facilitated.

Another important object of this invention is to provide an arrangement of cylinders for the aforementioned two-color direct letterpress which enables the easy conversion from letterpress printing to lithographic or other offset printing, while still enabling easy access to all of the cylinders by the operator from a single position for the reasons aforementioned.

A printing press of the type contemplated herein is one which utilizes flexible shallow-relief etched plates when used for letterpress printing. Such plates may be of zinc, magnesium, aluminum, or any of the new thin plastic plates provided with sheet metal backing or other means for maintaining dimensional stability of the plate. When using such thin, flexible plates for direct multicolor printing on the press about to be described, it is necessary to provide make-ready packing procedures beneath the plates and their cooperating tympan cylinders to compensate for the attendant length-of-print differences which come about when plates having different image-area coverages are used. For a better understanding of lengthof-print problems which occur when using such plates, one may refer to the co-pending application of C. C. Harris et al., Ser. No. 179,588, filed March 14, 1962. Suffice it to say here that a thin, flexible plate which is processed while in the flat, has an overall image growth in a circumferential direction when wrapped about the peirphery of a cylinder. Assuming that the image areas of a first plate provide substantial solid printing as compared to a second plate which has a very minimum of image area, the first plate will have an image growth slightly less than the second when curved about a cylinder of the identical diameter. This is due in part to the fact that the neutral bending axis of the first plate will be at a slightly greater radius from-the cylinder axis than the second plate because of its effective greater plate thickness as determined by the extent of image area. In addition, the first Plate, in printing solids, appears to have a greater ironing out action on a sheet of paper than the second sheet. The greater the ironing out effect,

the shorter will be the image printed by the plate, due

of the image area of such plate against the stock would increase unless corrected. Proper printing pressure can be restored on certain presses by widening the distance between the plate and impression cylinder axes without affecting the impression cylinder diameter. Or, in the case of a printing unit having impression and plate cylinders on centers which are not adjusted for stock thickness or printing pressure, due, for example, to running of said cylinders in bearer contact while printing, compensation can be made by providing a tympan sheet and customary packing therebeneath on the impression cylinder, and adjusting the tympan packing thickness to correspond to any adjustment made in plate cylinder packing.

When tympan make-ready on an impression cylinder is necessary for controlling printing pressure, it becomes commercially impractical to use so-called common impression printing, i.e., printing by two or more plate cylinders against a single or common impression or tympan cylinder. This isdue in large part to the aforementioned length-of-print problems. If the image areas of both plates are substantially the same, the packing beneath both plates will ordinarily be the same thickness, and proper common impression printing can be obtained. But, if the packing thickness beneath one plate must necessarily differ from that of the other for lengthof-print compensation, the higher-packed plate will press against the stock with greater printing pressure, oftentimes embossing the stock. This will be true even though the tympan packing of the common impression cylinder is changed to attempt to strike a happy medium between the two different pressures from the different plates.

Obviously, for any printing press to be commercially acceptable, accessibility must be available to any cylinder which requires make-ready, and this accessibility should be relatively easily accomplished. Preferably, in a two color printing press of this general type, all makeready should be accomplished from a single operators station to facilitate not only the task of installing various arrangement adapted for printing by the direct letterpress process.

FIG. 2 is a view of a portion of the press illustrated in FIG. 1 with the cylinders having been converted to print by the lithographic offset process.

FIG. 3 is a view of the upper printing unit of FIG. 1, looking approximately from the left thereof.

Since the same elements of the printing press are adapted to enable printing by more than one process, the numerals for certainelements in the different views will be the same. However, the parts will be designated with the letter a for direct letterpress and b for lithographic otfset, primarily because certain parts are called by different names, depending upon which printing process is being utilized. It will be seen that the direct letterpress of FIG. 1 has a first printing unit 16a and a second printing unit 11a while the lithographic offset press of FIG. 2 has a first printing unit 10b and a second printing unit 1112. In the first uni-t 10a there is a tympan cylinder 120, a plate cylinder 13a, and an inking cylinder 14a. offset press of FIG. 2 are an impression cylinder 1211, a blanket cylinder 13b, and a plate cylinder 14b. To

The corresponding cylinders of the lithographic facilitate an understanding of the method of claiming hereinafter, the cylinders 12:: and 12!) are referred to as impression cylinders, the cylinders 13a and 13b are referred to as intermediate cylinders, and the cylinders 14a and 1412 are referred to as third cylinders. Since. the two types of presses of FIGS. 1 and 2 will be described separately however, it is necessary to understand such terminology only for purposes of claiming.

Referring now to FIG. 1, sheets are fed from a pile 15 in any conventional manner to take-out rolls 16 and then along a substantially horizontal but slightly downwardly inclined feed table 17. It is to be understood that the direction of sheets from the pile 15 along the feed table 17 is referred to as the forward direction, and that any mention of location of any of the elements as being forward or to the rear of any other element is related to the direction of sheets from right to left as viewed in FIG. 1. Sheets are temporarily arrested and front and side registered at the forward end of the feed table 17, and then fed to grippers 18 on the tympan cylinder 12a. They are taken by the grippers and passed through a printing nip between the cylinders 12a and 13a in which they receive an imprint from a relief printing plate 19 on cylinder 13a. They then travel further around the cylinder 12a while held by the grippers 18 and are transferred to grippers 20 on a transfer cylinder 21. Grippers 20 transfer the sheet to grippers 22 on a second tympan cylinder 23a which carries the sheet through a printing nip formed by the cylinder 23a and a second plate cylinder 24a. The cylinder 24a carries a plate 25 which may be similar to the plate 19 on cylinder 13a. After having been printed in the nip between the cylinders 23a and 24a, the grippers 22 deliver the sheet to grippers 26 which comprise a portion of a delivery means 27. Such delivery means is of well known construction and will be described only to the extent necessary to fully understand and appreciate the invention claimed herein. The grippers 26 are carried as individual assemblies by a pair of conventional continuous chains 28 which pass around sprockets 29 carried at the ends of a delivery cylinder 30. Upon receiving a sheet from the grippers 22 of the second tympan cylinder 23a, the delivery grippers 26 transport the sheets around the delivery cylinder 30 downwardly and forwardly below a transverse platform 31 supported by frame members 32 at opposite ends thereof. The grippers 26 deliver the sheets one at a time to a conventional delivery pile (not shown).

The first and second printing unit 10a, 11a are provided with inkers 33 and 34 respectively. The inker 33 is preferably located directly vertically above the inking cylinder 14a while the inker 34 is located forward of and below a second inking cylinder 35a which is in rolling contact with the plate cylinder 24a. The inker 34 is preferably of the known roll-back type and can be selectively moved between the full-line operative posi- I tion and the dotted-line, inoperative position shown in FIG. 1.

The relative sizes of the parts are such that the top of the inker 33 is above the level of the platform 31 to such an extent that an average height operator positioned at platform 31 can reach an ink fountain 36 to perform normal operations in connection therewith. By being positioned at platform 31, the operator has access to all of the cylinders 12a, 13a, 14a 23a, 24a and 35a for all normal work performed on such cylinders by a pressman.

The tympan cylinders 12a and 23a are preferably of the construction shown in the copending application of R. K. Norton, Serial No. 22,760, filed April 18, 1960. For example, the cylinder 12a may have a tympan sheet 37 fastened in a clamp 38 adjacent the grippers 18. At

. the time the sheet is fastened to the cylinder 12a, the

clamp 38 will be adjacent the position of the arrow 39. The press may be jogged forward until the cylinder 12a is rotated to a position wherein a tympan reel rod 40 of the type shown in the aforesaid Norton application is adjacent the arrow 39, at which time the tympan sheet 37 can be inserted into the rod 40 and tensioned on the cylinder 12a in customary fashion. The mounting of a tympan sheet on the cylinder 23a may proceed in the same fashion, with the insertion of the lead edge of the tympan sheet into its clamp taking place at the point of the arrow 41. It will be understood that the reel rod on the cylinder 23a will also be located in approximately that same position when the trailing edge of the tympan sheet to be mounted on the cylinder 23a is inserted therein and tensioned about the cylinder.

The relief printing plates 19 and 25 to be mounted on the cylinders 13a and 24a respectively may be of the flexible, shallow-relief etched type which may be made of zinc, magnesium, aluminum, photopolymer plate, etc.

Inking cylinders 14a and 35a are adapted to receive rubber blankets 42 and 43 respectively. The blankets 42 and 43 are preferably adapted to carry blanket bars or strips at their leading and trailing edges to be received in clamps 44 and 45 at the lead edges respectively and reel rods 46 and 47 at their trailing edges respectively. The blankets are mounted on their inking cylinders 14a and 35a in the same general fashion as the tympan sheets are located on their cylinders 12a and 23a. Blanket 42 is placed on cylinder 14a in the direction of arrow 48 and blanket 43 is placed on cylinder 35a in the direction of arrow 49.

The installation of the plates 19 and 25 on cylinders 13a and 24a respectively is accomplished by inserting them into leading and trailing edge plate clamps. Since such installation is substantially the same on both cylinders 13a and 24a, it will be described with reference only to cylinder 13a. The press is jogged until the leading edge plate clamp 50 is positioned adjacent the point of arrow 51 to receive the plate in the clamp jaws thereof. As is customary in the make-ready techniques of printers, the press is further jogged preferably under pressure between the inking cylinder 14a and the plate cylinder 13a to roll the plate 19 tightly against the cylinder body 13a. After this is sufiiciently accomplished around the major portion of the cylinder 13a, the trailing edge of the plate is then inserted into the trailing edge clamp 52, locked in the jaws thereof, and tensioned in the customary fashion. It will be noticed that the cylinder 13a is adapted to be bodily moved between its printing or pressure position shown in full lines and an inoperative or throwoff position shown in dotted lines. This movement may be accomplished by conventional eccentrics which are well known in the art. In order to properly mount the plate 19 on the cylinder 1301, it is sometimes desired to roll the plate against the blanket 42 on the inking cylinder 14a under pressure as previously described. Accordingly, the plate cylinder should be installed after the installation of the flexible blanket on the inking cylinder 1401.

Installation of the plate 25 On the cylinder 24a is performed in the same fashion as that described for plate 19 and is accomplished in the direction of arrow 53.

It will be seen from the foregoing that all of the tympan sheets, plates and blankets can be easily installed on their respective cylinders from one side of the two-color printing unit by an operator positioned at the platform 31. In addition to facilitating this make-ready technique, it will be seen that a substantial portion of each of the aforementioned cylinders faces the operator to enable him to clean large areas thereof during the necessary washup procedures, etc. Accessibility to the transfer cylinder 21 may be obtained by an operator crouching below the feed table 17. However, accessibility to cylinder 21 is ordinarily not necessary when changing from one printing job to the next, while it is extremely necessary to obtain access to the remaining cylinders.

Each of the cylinders 12a, 13a, 14a, 23a, 24a and 35a is preferably provided with continuous bearers at the ends thereof as disclosed in the aforementioned Harris et al. application Ser. No. 179,588. Bearers 12c, 13c, and 140 are shown in FIG. 3 for cylinders 12a, 13a, and 1411, respectively. These bearers run in rolling pressure contact during the printing operation and provide stability of the cylinders of the printing couple in wellknown fashion. Because of the bearers, a stock thickness adjustment cannot be made between cylinders 12a and 13a or cylinders 23a and 24a in the customary manner in which this is accomplished in a standard lithographic press, for example. The usual lithographic press has bearers between the plate and blanket cylinders, but bearers are not used on impression cylinders except in rare, isolated cases where the press is used for printing the same thickness stock all of the time. Consequently, eccentrics for mounting the blanket cylinder can be adjustably rotated to move the blanket cylinder toward or away from the impression cylinder in a conventional lithographic press.

Whenever a packing change is required beneath the plate 19 on cylinder 13a, the packing thickness under the blanket 42 must be adjusted to provide the proper pressure relationship between the blanket 42 and the plate 19 for correct transfer of ink to the plate. At the same time, the packing under the tympan sheet 37 on the cylinder 12a must be likewise adjusted so that proper printing pressure is applied to the sheets fed through the nip between cylinders 12a and 13a.

While I prefer to use bearers on each of the three cylinders of each printing unit, thus necessitating the use of make-ready techniques on cylinders 12a and 23a, it may be desirable in some instances and necessary in others to provide for packing under the tympan sheets even though bearers may not be used on the tympan cylinders. For example, the structure of the printing press may not enable movement of the centers or axes of cylinders 12a or 13a toward and away from each other to compensate for change of stock thickness. Accordingly, whenever the axes of the plate and tympan cylinders are relatively nonadjustable for stock thickness compensation, whether it be because of contacting bearers on such cylinders or because of other structural reasons, it can be seen that the objects of my invention can be accomplished in a facile manner. For example, the make-ready techniques which are possible on cylinders 12a and 23a permit the use of flexible letterpress plates on cylinders 13a and 24a which may differ widely in their extent of image-area coverage, and,

this can be accomplished while obtaining the exact desired printing pressure at each unit without comprising between the two different height plates 19 and 25, such as would be necessary in the case where a common tympan cylinder is used for both plate cylinders.

Referring now to FIG. 2, it is to be understood that those parts such as platform 31 not illustrated in FIG. 2 but illustrated in FIG. 1 are also present in the lithographic offset press. The lithographic offset press is additionally provided with a first printing unit dampener 54 and a second printing unit dampener 55. Since the printing press may be adapted to be converted by an operator from one arrangement as shown in FIG. 1 to the other arrangement shown in FIG. 2, the dampeners 54 and 55 preferably remain in their respective frame members on the press at all times. They will be in their operative positions shown in FIG. 2 only when used for printing by the lithographic process, but will be moved out of such positions so as not to contact the inking cylinders 14a and 35a when used in the direct letterpress process.

The printing press can be converted from use with one process to the other by utilizing the invention of US. application Ser. No. 107,197, of R. K. Norton and H. A. Pritchard, filed May 2, 1961. In such application, it will be seen that the third and intermediate cylinders of each printing unit can be converted so as to enable practice by either process. In such case, for example, in changing from the direct letterpress arrangement to the lithographic arrangement, the reel rod 46 on the cylinder t 6 14a of FIG. 1 may be removed therefrom, turned end-forend, and installed on the blanket cylinder 13b of the FIG. 2 arrangement. In addition to this, the trailing edge plate clamp 52 on the plate cylinder 13a of the FIG. 1 arrangement may be removed, turned end-for-end, and installed on the plate cylinder 14b of the FIG. 2 arrangement asshown. If desired, the gaps in the cylinders 13 and 14 may be provided with insertsmounting the plate or blanket clamps, the entire inserts being interchangeable between the cylinders whenever desired. Also, if desired, the clamps may be made to receive either a printing plate or a blanket and remain on their respective cylinders.

While the press is intended to be converted between the two processes in the field by a pressman, the advantages of my invention also enable desirable manufacturing conveniences and standardization of parts in those instances where a press is to be used for only one or the other of the two processes, but not both.

It will be noticed from thedirections of the various arrows to the left of FIG. 2 which correspond to similar arrows in FIG. 1, that the plates, blankets and tympan sheets can all be installed from the same side of the press by an operator positioned at the platform 31. While lithographic presses do not customarily have tympan sheets mounted on their impression cylinders 12b and 23b, in those instances when the press is built to be convertible in the field by the press operator, it is desirable to use an impression cylinder which carries a tympan sheet so as to bring the impression surface to the proper height for printing by either process. In those instances, however, where the press is intended for field use with one process only, and where the arrangement is taken advantage of primarily for manufacturing convenience and standardization of parts, the cylinders 12!; and 23b will be of the conventional impression cylinder type having a metal surface or periphery of the proper height.

As mentioned in the aforesaid Norton and Pritchard application, my cylinder arrangement is useful also for printing by the so-called dry offset process.

Various changes may be made in the details of construction and arrangement of the parts without departing from the spirit and scope of the claims.

Having described my invention, I claim :1

1. In a two-color rotary printing press for printing directly onto print-receiving material from thin, flexible, shallow-relief printing plates,

a first tympan cylinder,

a first plate cylinder adapted to run in rolling contact with the first tympan cylinder,

inking means comprising a first inking cylinder adapted to run in rolling contact with a printing plate on the plate cylinder,

all of said cylinders being the same diameter and said plate and inking cylinder being located generally vertically above said first tympan cylinder,

means for presenting print receiving material into a printing nip formed by the first plate and tympan cylinders,

a bearerless transfer cylinder of the same diameter as said other cylinders and situated below the first tympan cylinder,

a second tympan cylinder adjacent said transfer cylinder with its axis below and forward of the axis of the transfer cylinder,

a second plate cylinder adapted to run in rolling contact with the second tympan cylinder with its axis being approximately in the same horizontal plane as the second tympan cylinder,

inking means comprising a second inking cylinder adapted to run in rolling contact with a printing plate on the second plate cylinder and having its axis below and forward of the axis of the second plate cylinder,

all of said second cylinder-s being of the same diameter as the first cylinders and each of said first and second tympan, plate and inking cylinders having continuous bearers at each end thereof running in rolling pressure contact with other bearers on the adjacent bearer-carrying cylinder or cylinders,

means for mounting flexible printing plates about a major portion of the peripheries of said first and second plate cylinders,

means for mounting flexible tympan sheets about the peripheries of each of said first and second tympan cylinders,

means for mounting flexible, resilient ink-transferring "blankets about a major portion of the peripheries of each of said inking cylinders,

horizontal platform means adjacent and forward of the second inking cylinder providing for operator access to said first and second plate, tympan and inking cylinders from said platform for installation of plates and, tympan sheets and blankets thereto respectively,

and means for delivering the print receiving material from the second tympan cylinder below and beyond the platform means.

2. A rotary printing press according to claim 1 wherein the means for mounting plates and blankets respec- 8, tively on said first and second plate and inking cylinders are each removable therefrom, and wherein each of said first and second plate and inking cylinders includes means for interchangeably mounting either said plate or blanket mounting means thereon.

References Cited by the Examiner UNITED STATES PATENTS 1,358,843 11/1920 Grass 101143 X 1,459,312 6/ 1923 Pritchard 101-137 1,471,895 10/1923 Huebner 101217 X 2,270,272 1/1942 Davidson 101217 X 2,542,867 2/ 1951 Harrold 101137 2,619,901 12/1952 Harrold 101177 2,702,002 2/1955 Koch 101136 FOREIGN PATENTS 361,048 11/ 1931 Great Britain.

418,437 10/1934 Great Britain.

783,983 10/1957 Great Britain.

EUGENE R. CAPOZIO, Primary Examiner. 

1. IN A TWO-COLOR ROTARY PRINTING PRESS FOR PRINTING DIRECTLY ONTO PRINT-RECEIVING MATERIAL FROM THIN, FLEXIBLE, SHALLOW-RELIEF PRINTING PLATES, A FIRST TYMPAN CYLINDER, A FIRST PLATE CYLINDER ADAPTED TO RUN IN ROLLING CONTACT WITH THE FIRST TYMPAN CYLINDER, INKING MEANS COMPRISING A FIRST INKING CYLINDER ADAPTED TO RUN IN ROLLING CONTACT WITH A PRINTING PLATE ON THE PLATE CYLINDER, ALL OF SAID CYLINDERS BEING THE SAME DIAMETER AND SAID PLATE AND INKING CYLINDER BEING LOCATED GENERALLY VERTICALLY ABOVE SAID FIRST TYMPAN CYLINDER, MEANS FOR PRESENTING PRINT RECEIVING MATERIAL INTO A PRINTING NIP FORMED BY THE FIRST PLATE AND TYMPAN CYLINDERS, A BEARERLESS TRANSFER CYLINDER OF THE SAME DIAMETER AS SAID OTHER CYLINDERS AND SITUATED BELOW THE FIRST TYMPAN CYLINDER, A SECOND TYMPAN CYLINDER ADJACENT SAID TRANSFER CYLINDER WITH ITS AXIS BELOW AND FORWARD OF THE AXIS OF THE TRANSFER CYLINDER, A SECOND PLATE CYLINDER ADAPTED TO RUN IN ROLLING CONTACT WITH THE SECOND TYMPAN CYLINDER WITH ITS AXIS BEING APPROXIMATELY IN THE SAME HORIZONTAL PLANE AS THE SECOND TYMPAN CYLINDER, INKING MEANS COMPRISING A SECOND INKING CYLINDER ADAPTED TO RUN IN ROOLING CONTACT WITH A PRINTING PLATE ON THE SECOND PLATE CYLINDER AND HAVING ITS AXIS BELOW AND FORWARD OF THE AXIS OF THE SECOND PLATE CYLINDER, ALL OF SAID SECOND CYLINDERS BEING OF THE SAME DIAMETER AS THE FIRST CYLINDERS AND EACH OF SAID FIRST AND SECOND TYMPAN, PLATE AND INKING CYLINDERS HAVING CONTINUOUS BEARERS AT EACH END THEREOF RUNNING IN ROLLING PRESSURE CONTACT WITH OTHER BEARERS ON THE ADJACENT BEARER-CARRYING CYLINDER OR CYLINDERS, MEANS FOR MOUNTING FLEXIBLE PRINTING PLATES ABOUT A MAJOR PORTION OF THE PERIPHERIES OF SAID FIRST AND SECOND PLATE CYLINDERS, MEANS FOR MOUNTING FLEXIBLE TYMPAN SHEETS ABOUT THE PERIPHERIES OF EACH OF SAID FIRST AND SECOND TYMPAN CYLINDERS, MEANS FOR MOUNTING FLEXIBLE, RESILIENT INK-TRANSFERRING BLANKETS ABOUT A MAJOR PORTION OF THE PERIPHERIES OF EACH OF SAID INKING CYLINDERS, HORIZONTAL PLATFORM MEANS ADJACENT AND FORWARD OF THE SECOND INKING CYLINDER PROVIDING FOR OPERATOR ACCESS TO SAID FIRST AND SECOND PLATE, TYMPAN AND INKING CYLINDERS FROM SAID PLATFORM FOR INSTALLATION OF PLATES AND, TYMPAN SHEETS AND BLANKETS THERETO RESPECTIVELY, AND MEANS FOR DELIVERING THE PRINT RECEIVING MATERIAL FROM THE SECOND TYMPAN CYLINDER BELOW AND BEYOND THE PLATFORM MEANS. 